There has been a great increase in the development of RF components, especially in mobile stations and similar such devices. The advancement of mobile stations has prompted the increase in the number of RF components that require production line and service testing of RF signals for conformance to government and industry standards. The testing and characterization of these RF signals has been important to quality control in the production and repair of mobile terminals.
The complexity of wireless devices is increasing, and as a result, this requires more testing time for the individual RF components. Costs are typically determined by such factors as labor and the number of test devices needed. As in any mass production undertaking, optimizing these cost factors is an important consideration.
For reasons of expediency of both production and servicing it is optimal to test RF signals from RF components without dis-assembling the host wireless device. Also, it is preferable to conduct RF testing without a connected antenna in order to measure RF output power accurately. In the testing of receiver circuits, a connected antenna can receive interference signals, thus preventing the accurate testing of the receiver circuits. It is preferred to conduct RF testing without a connected antenna in order to limit the undesirable transmission of RF energy from the antenna. This undesirable transmission can interfere with surrounding electrical equipment. There have been methods provided in the prior art for testing RF devices, which, when used in servicing a mobile station, generally require the removal of the antenna, housing, or other components. In some types of mobile stations, the antenna must first be removed to allow for RF testing of the antenna connection. In addition, the mobile station must usually be dis-assembled into various parts.
In the manufacture of mobile stations, RF testing is usually first conducted prior to complete assembly. Such testing is usually followed by final assembly and a further RF test of the fully assembled device. This method is repetitious and inefficient, and further exposes the device and its internal components to damage that could frustrate other quality controls.
In a service center it is possible to install new software on a malfunctioning mobile station with little or no disassembly of the device. Afterwards, the mobile station typically requires testing prior to being returned to the customer. It would be advantageous if the mobile station could be RF tested in the service center without dis-assembly to identify and isolate malfunctioning component(s).
Sometimes an antenna must be removed in a service center, exposing it to damage. Some wireless devices contain an aperture for RF testing. However, these apertures can expose sensitive internal components to damaging environmental factors such as moisture or dust during normal use by the customer. Such contamination may also enter if a mobile station's housing is breached during testing that requires dis-assembly. One example of an aperture is in U.S. Pat. No. 6,469,673, which describes an aperture in a planar radiator element of a mobile station for testing of RF signals. Apart from the advantages it offers, this aperture appears to provide for the above-mentioned environmental exposure.
Some mobile stations protect against environmental contaminants such as water and dust by including more occlusive seals, some of which are water resistant. Minor additional expense associated with these more occlusive seals is justified by the increased longevity of the internal components, which remain better protected. However, such seals also make routine maintenance more difficult and raise maintenance expenses.
Some mobile stations include a specific RF connector on the printed wire board that is dedicated to RF testing only, and provides no direct advantage to the customer. It would be useful to remove this kind of connector, as it adds to the cost and the required printed wire board area.
What is needed in the art is an apparatus and method for testing RF components that are internal to a wireless device without requiring the device be dis-assembled, and/or without leaving the internal components exposed to environmental contaminants such as dust or water during normal use.